Tech Tips with Steve Turchet

I bought a new transmission for my 1963 M151. Can I replace the transmission without removing the engine? — Frank Bell

Yes, if you really want to. However, MUTTs were designed to have their engines and transmissions removed as a unit, and you will probably find it much simpler and easier to remove them as such to replace your transmission.

The Blues

I have a M151A1 that I use for a daily driver. I have had it about five years, and it runs fine. For about the last year, however, it has started to give off blue smoke out of the exhaust pipe when I start it, but then the smoke stops after a few minutes. I know blue smoke means oil burning, and it might be the rings, If the problem is worn rings, wouldn’t it keep smoking? — Dave T.

One of the most likely causes of blue smoke after startup that clears up after a few minutes, especially on OHV type engines, are worn valve stem seals and/or guides. Oil seeps into the cylinders after warm engine shutdown, which causes blue smoke for a few minutes when it’s started again. On the other hand, on engines with worn piston rings the smoking usually gets worse as the engine warms up.

Wheelwright Or Wheel Wrong

I bought an NOS steering wheel for my 1966 M37B1. I am having a lot of trouble removing the old wheel. I don’t want to damage the steering column. The wheel is really stuck on tight. I borrowed a friend’s steering wheel puller, but it won’t fit the M37 wheel. Any suggestions? — Tom

The best way to remove any vehicles’s steering wheel without damaging it or possibly also the steering column is with the proper type puller. In the case of your M37, as well as many other common HMVs, the military “C-type” puller usually works best.

Back In Black

I have had my 1957 M37 for about a year. It is a great truck. I am slowly restoring it back to original. I bought an NOS air cleaner that was still in a box. It is black. Is this the right color? My old one is Army olive drab. — W. Connor

Most M37s, as well as many other common U.S. military vehicles, came from their factories with black air cleaners. Over the years, many were painted OD, either while in military service or by later civilian owners. But, again, the factory color was almost always black.

Big Problem?

I found a stock winch for my M37 on a junk M37 in a wrecking yard. It looked okay. There was also the PTO and drive shaft. I installed it on my truck, put in new oil, and it worked. I installed new cable. But when I went to pull something heavy to test it, the winch slipped, made a clunking sound, and wouldn’t pull. A friend said the gears were probably stripped, so the winch is junk. Could there be anything else wrong with it except a big problem? —Terry Clarke

After making sure the shear pin didn’t break, I would check the winch shift collar yoke adjustment. Sometimes this gets loose and the shifter dogs don’t fully engage and will pop out under load. Hopefully, this is your problem and not a stripped gear.

Large Charge

All lead-acid vehicle batteries will become discharged when stored for long periods of time, either in or out of a vehicle. Most of today’s auto computers and radios draw a tiny amount of current at all times. And, many vintage M-series HMVs with 24-volt generators have a capacitor in the voltage regulator that also constantly draws a tiny amount of current. This isn’t a lot — you will need a sensitive test meter to even measure it. But, it’s enough to discharge a battery over a long period of time in a vehicle that isn’t being used.

Batteries will also slowly self-discharge without any load connected, just like all tires will eventually lose air. Another factor that weakens lead-acid batteries is called “sulfation.” This is basically a layer of crud that builds up on the plates from long periods of slow discharge. It’s caused by a reaction between the lead plates and the sulfuric acid inside a battery. A quick charge will not remove it, though a long trickle charge can.

I’ve seen many dead or almost dead batteries in vehicles that were sitting for long periods of time. Even after a massive fast-charge, the batteries were still weak, but after a few days on a trickle charger most were much stronger, and many served for over a year afterward.

This is a good reason to check the date code of batteries on the shelves of auto stores before you buy them. If a battery has been on the shelf for over a year, buy one somewhere else.

If you’re putting a vehicle in storage or not planning to use it for several months, take the battery out and charge it about every three weeks. You could also buy a regulated trickle charger designed to keep a battery in good condition over long periods.

Can’t Stop Stopping

I have a G-506 1-1/2-ton truck. The right front wheel won’t release the brakes after I take my foot off the brake pedal. The brakes drag or stay locked up. The brakes on the other wheels work fine. I checked the steel brake line to the right front wheel but I can’t see any flat places. What could be the problem? — Trey Sanders

Most likely, the rubber hose from the steel brake line to the right front wheel is deteriorated inside. This is a common problem with old brake hoses. Stepping on the brake pedal creates enough pressure to apply the brake shoes, but the return springs aren’t strong enough to force the fluid back to release the shoes. Replacing the hose should solve the problem. It would be smart to replace all the others if they’re the same age.